I NEED HELP ASAP IN ON TIMER Why was Becquerel’s experiment a first step in discovering radioactivity?

A. It showed that a substance could phosphoresce when it was not exposed to light.

B. It showed that the substance that was used by Becquerel could phosphoresce.

C. It showed that a substance could constantly emit radiation even if it was not exposed to light.

D. It showed that a substance emitted radiation when it was exposed to light.